Air blowing nozzle



May 1967 H. H. HERING, JR. ETAL 3,319,354

AIR BLOWING NOZZLE Filed Nov. 13, 1964 2 Sheets-Sheet 1 INVENTQRS Henry H. Her-mg,J/7

diff 5 y 16, 7 I H. H. HERING, JR. ETAL 3,319,354

AIR BLOWING NOZZLE Filed Nov 13, 1964 2 Sheets-Sheet 2 Vi ctor' I Capizzz FIG 7 W M g J m I/E/V (0&3 Henry H. HermgJn United States Patent 3,319,354 AIR ELDWENG NQZZLE Henry H. Hering, In, Homewood, and Victor T. Capizzi, Chicago, Ill., assignors to B. ()ffen & Co. Inc., Chicago, Ill., a corporation of Iilinoi-s Filed Nov. 13, 1964, Ser. No. 410,996 13 Claims. (Cl. 34-455) This invention relates to nozzle constructions of the type adapted to discharge air in web drying means. In particular, the invention is concerned with nozzle constructions suitable for use in air driers which are capable of handling webs moving at relatively high speeds.

This application is a continuation-in-part of applicants copending application Ser. No. 358,900, filed Apr. 10, 1964.

There are many applications which require the drying of webs of material, including paper, cloth fabrics and the like. In one such application, webs are printed with ink, and the ink must be dried on the webs before the web surfaces are brought into contact with each other or with other objects. The instant invention will be described with reference to webs which have been printed whereby the ink thereon must be dried. It will be understood, however, that the apparatus to be described will have other applications in web drying.

There are many structures available capable of providing the necessary conditions for the drying of webs. Conventional constructions sufler from many defects, however, since the printed surfaces are in many cases brought into contact with rollers or similar supporting means and damage to the printed material often results. Furthermore, conventional units are incapable of providing high speed performance and, accordingly, their efficiency is limited to a significant degree.

Constructions such as described in the Gautreau Patent No. 2,144,919 have been devised whereby web drying could be accomplished without contact of the web surface with solid objects. In this arrangement, the web is passed between a plurality of outlet means which are adapted to direct air streams into contact with the web surfaces. The streams serve to support the web and maintain it out of contact with other surfaces while the streams also effect drying of the web. Structures of the type described in this patent have, however, been incapable of achieving efficient drying when high speed operations were required.

In the aforementioned copending application, an improved mechanism is described which provides for the drying of webs in a highly efiicient manner. The nozzle construction for the air discharge means comprises air outlets in the form of a plurality of slots with the respective slots providing for the discharge of narrow and substantially continuous streams of air for contact with a web surface. The particular configuration of the nozzles provides an air discharge which is uniquely suitable for effecting the necessary drying and, in addition, the particular nozzle construction can be produced in a very efficient manner.

It is an object of the instant invention to provide means for improving the efiiciency of air streams which are passed out of nozzles into contact with a web surface.

It is one particular object of this invention to provide an improved means adapted to be associated with nozzles of the type described in the aforementioned copending application whereby the air streams discharged from said nozzles can accomplish drying in an extremely effective and efficient manner.

These and other objects of this invention will appear hereinafter and for purposes of illustration, but not of limitation, specific embodiments of this invention are shown in the accompanying drawings in which:

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FIGURE 1 is an enlarged cross-sectional view of one form of nozzle means utilizing the improvement of this invention;

FIGURE 2 is a diagrammatic elevational view illustrating the nozzle means of FIGURE 1 when associated with air duct means in a web drier;

FIGURE 3 is a fragmentary side elevational view of an alternative arrangement of nozzle means;

FIGURE 4 is an enlarged fragmentary cross-sectional view of nozzle means of the type shown in FIGURE 3;

FIGURE 5 is a fragmentary plan View taken about the line 5-5 of FIGURE 3;

FIGURE 6 is a cross-sectional view of the nozzle drying assembly taken about the line 66 of FIGURE 3; and,

FIGURE 7 is an enlarged detail view, in section, illustrating an alternative form of the improvement of this invention when associated with nozzle means of the type shown in FIGURES 3 through 6.

The improvement of this invention is generally applied to an apparatus employed for the drying of a continuous web. Such an apparatus may comprise air duct means with nozzles formed in said duct means. Each of the nozzles defines outlet openings and blowers or similar mechanisms are provided for forcing air through the duct means and out the nozzle openings for contact with at least one surface of a web passing through the apparatus.

The particular improvement of this invention concerns baffie means which are associated with the nozzles and which are disposed on opposite sides of the outlet openings. The nozzles define additional openings whereby air will also be discharged through the additional openings into contact with the baffles. The baffles are of a configuration whereby the air from the additional openings is directed toward the web surface. Since these openings are located on opposite sides of the main outlet openings for the nozzle, the air from the main openings will be confined between the air from the additional openings. It has been found that this arrangement greatly improves the drying efficiency when constructions employing the improvement of this invention are compared to identical constructions lacking the improvement of this invention.

FIGURES 1 and 2 of the accompanying drawings illustrate an arrangement suitable for the utilization of the improvements of this invention. An air duct means 10 communicates with upper nozzle 12 and lower nozzle 14 whereby air can be passed into contact with both surfaces of a web 16 passing between the nozzles. It will be understood that a plurality of the nozzles 12 and 14 can, and usually would be, employed whereby contact with the web surfaces by different drying air streams would be accomplished during travel of the web through a drying apparatus. It will also be understood that the nozzle construction of FIGURES 1 and 2 as well as the constructions shown in the remaining figures, could be employed in an arrangement wherein air streams contact only one surface of the web.

The nozzles 12 and 14 define a generally tear-shaped cross section with each nozzle being provided with converging side walls 18. The edges 20 of these side walls are spaced apart whereby an aperture 22 is formed between the edges. These apertures extend parallel to the web surfaces to define outlet openings in closely spaced relationship to these surfaces. It will be apparent that air passing through the outlet openings will define a narrow stream.

Baffles 24 are attached to the converging side walls of each of the nozzles 12 and 14. In the embodiment illustrated, the bafiies comprise sheet metal members which define U-shaped portions 26 and 28. The U-shaped portions 28 receive the side walls of the nozzles whereby the 3 bafiiescan be clamped onto or otherwise secured to these nozzles.

The side walls 1%; of the nozzles define openings while the legs of the U-shaped portion 28 define corn municating openings 32 and 34. It will be apparent that air is adapted to pass through these communicating openings whereby it will engage the surfaces 36 of the U- shaped portions 26. Since these surfaces are directed angularly inwardly, streams of air will be similarly directed so that these streams will confine the stream from the main outlets 22.

FIGURE 3 illustrates a modified design wherein duct means 49 communicate with a plurality of nozzles 42. Each of these nozzles 42 includes an end face 44- and a plurality of slots 46 defined therein. In the illustrated embodiment, the slots are formed in adjacent rows in staggered relationship whereby air issuing from the slots in a given row will tend to form a continuous stream across the width of the web. A pair of such rows are located adjacent the side edges of the face 44 so that each nozzle provides for the discharge of two substantially continuous air streams.

The side walls 48 of the nozzles 42 define openings 50 whereby air in the nozzles can also discharge from the side walls. Bafiles 52 are attached by means of screws 54 to the side walls so that the issuing air streams will be directed toward the web surface.

In the operation of a drier of the type shown in FIG- URE 4, blowers 56 force air into duct means 4t) and into nozzles 42. Air issuing from the outlets 50 will tend to be drawn inwardly due to the movement of the streams issuing from the slots 46. Accordingly, the streams from the slots 46 are confined by the streams from the openings 50.

FIGURE 7 represents a modification from the construction shown in FIGURE 4 in that the bafiies 56 shown therein include end portions 58 which bend angularly inwardly toward the slots 46. Accordingly, air issuing from the openings 50 will be more positively directed for confinement of the air issuing from the slots.

It has been found that in normal nozzle operation without the improvement of this invention, the discharge streams pick up ambient air. This results in the formation of a negative pressure between the nozzle and the web whereby a rapid vibration between the nozzle and web can result.

It will be apparent that each of the constructions illustrated herein provides for the directing of auxiliary air streams into contact with a main stream. The particular arrangements have been found to greatly improve the efirciency of a drying operation. It is believed that the primary reason for the improvements realized is the ability of the auxiliary streams to eliminate or minimize the forementioned entrainment of ambient air by the main streams.

A wide variety of combinations are possible with the improvement of this invention wherein a main drying stream is employed in combination with auxiliary streams. Thus, the openings 30 and 50 could comprise slots, circular holes or other configurations providing for the desired discharge. It is preferred, however, that whatever configuration these outlets assume, uniformity across the width of the apparatus should be maintained.

It has been found that the provision of air discharge in the auxiliary streams comprising about 25 percent of the volume of the main stream provides highly satisfactory results. It will be appreciated that the amount of discharge from the auxiliary streams can be controlled by controlling the size and location of the outlet openings, and in this connection, it is contemplated that means could be provided for adjusting the size of these openings where the volume of auxiliary air discharge is to be adjusted.

In one specific arrangement, the openings 50 may comprise circular holes as shown in FIGURE 6. By selecting a proper size for these openings and a proper spacing of the openings, the volume of air comprising about 25 percent of the volume issuing from the adjacent slots 46 can be easily accomplished.

It will be understood that various changes and modifications may be made in the above described apparatus which provide the characteristics of this invention without departing from the spirit thereof particularly as defined in the following claims.

That which is claimed is:

ll. In an apparatus for the drying of a continuous web comprising air duct means, nozzles formed in said duct means, outlet openings defined by said nozzles, and means for passing air through said duct means for discharge out of said openings into contact with at least one surface of said web, the improvement comprising baffie means associated with said nozzles and disposed on opposite sides of said openings, additional openings defined by said nozzles adapted to pass air into contact with said baflles, said 'baffies being shaped to direct air from said additional openings towards said web surface with the air from said outlet openings being confined between the air passing from said additional openings.

2. An apparatus in accordance with claim 1 wherein said bafiie means include angularly, inwardly turned portions whereby the air from said additional openings is directed inwardly into contact with the air from said outlet openings.

3. An apparatus in accordance with claim 1 wherein said nozzles define two substantially parallel rows of air outlet slots extending crosswise of the path of movement of said web, the slots in adjacent rows being formed in staggered relationship, said slots defining said outlet openings and the combined slots in a given row providing a substantially continuous stream of air crosswise of said passage for contact with said web.

4. An apparatus in accordance with claim 3 wherein said nozzles define flat end faces extending parallel to said web surface and located in closely spaced relationship to said surface and wherein rows of said staggered slots are provided along both side edges of each of said nozzles.

5. An apparatus in accordance with claim 4 wherein said outlet openings are defined in the side walls of said nozzles adjacent the end faces thereof, and wherein said baffles are attached to said side walls.

6. An apparatus in accordance with claim 1 wherein said nozzles comprise converging side walls with the opposed edges of said side walls defining an elongated aperture, said edges extending parallel to the Web surface and being located in closely spaced relation thereto with the aperture of each nozzle defining an outlet opening, said additional opening being defined adjacent said edges and said baffles being attached to the outer surface of said side walls along said edges.

'7. In an apparatus for the drying of a continuous web comprising upper and lower ducts defining a passage therebetween for movement of said Web therethrough, nozzle means defined by each of said ducts, and means for passing air through said ducts for discharge out of outlet openings defined by said nozzle means and for contact with both surfaces of said web, the improvement comprising baffle means associated with said nozzles and disposed on opposite sides of said outlet openings, additional openings defined by said nozzles adapted to pass said air into contact with said bafiles, said baffles being shaped to direct air from said additional openings to- Ward said web surface with the air from said outlet openings being confined between the air passing from said ad ditional openings.

8. An apparatus in accordance with claim 7 wherein said baffle means include angularly, inwardly turned portions whereby the air from said additional openings is directed inwardly into contact with the air from said outlet openings.

9. An apparatus in accordance with claim 7 wherein said nozzles define two substantially parallel rows of air outlet slots extending crosswise of the path of movement of said web, the slots in adjacent rows being formed in staggered relationship, said slots defining said outlet openings and the combined slots in a given row providing a substantially continuous stream of air crosswise of said passage for contact with said web.

10. An apparatus in accordance with claim 9 wherein said nozzles define flat end faces extending parallel to said web surface and located in closely spaced relationship to said surface and wherein rows of said staggered slots are provided along both side edges of each of said nozzles.

11. An apparatus in accordance with claim 10 wherein said outlet openings are defined in the side walls of said nozzles adjacent the end faces thereof, and wherein said bafiles are attached to said side walls.

12. An apparatus in accordance with claim 8 wherein said nozzles comprise converging side walls with the op posed edges of said side walls defining an elongated aperture, said edges extending parallel to the web surface and being located in closely spaced relation thereto with the aperture of each nozzle defining an outlet opening, said additional opening being defined adjacent said edges and said bafiles being attached to the outer surface of said side walls along said edges.

13. An apparatus in accordance with claim 7 wherein said additional openings are dimensioned to discharge about 25 percent of the volume of air discharge from adjacent outlet openings.

References Cited by the Examiner UNITED STATES PATENTS 2,736,081 2/1956 Dungler 26-60 2,848,820 8/1958 Wallin et al 34156 X 3,230,636 1/1966 Daane 34-122 FREDERICK L. MATTESON, JR., Primary Examiner.

20 C. R. REMKE, Assistant Examiner. 

1. IN AN APPARATUS FOR THE DRYING OF A CONTINUOUS WEB COMPRISING AIR DUCT MEANS, NOZZLES FORMED IN SAID DUCT MEANS, OUTLET OPENINGS DEFINED BY SAID NOZZLES, AND MEANS FOR PASSING AIR THROUGH SAID DUCT MEANS FOR DISCHARGE OUT OF SAID OPENINGS INTO CONTACT WITH AT LEAST ONE SURFACE OF SAID WEB, THE IMPROVEMENT COMPRISING BAFFLE MEANS ASSOCIATED WITH SAID NOZZLES AND DISPOSED ON OPPOSITE SIDES OF SAID OPENINGS, ADDITIONAL OPENINGS DEFINED BY SAID NOZZLES ADAPTED TO PASS AIR INTO CONTACT WITH SAID BAFFLES, SAID BAFFLES BEING SHAPED TO DIRECT AIR FROM SAID ADDITIONAL OPENINGS TOWARDS SAID WEB SURFACE WITH THE AIR FROM SAID OUTLET OPENINGS BEING CONFINED BETWEEN THE AIR PASSING FROM SAID ADDITIONAL OPENINGS. 